Numerous distance measuring systems are known in the art and, by extension, so are systems which are able to resolve the motion of an object. Systems such as sonar, lidar, radar, and the like involve active emission of energy from a sensor to the object and thus such systems are often complex, expensive, and power intensive. The processing requirements underlying such systems are also typically intensive. Also, many prior systems may be fairly slow to acquire range information.
In fields such as robotics and portable navigation systems, fast, inexpensive, and low power ranging systems are desired.